Perforating machine with positive acting return



Feb. 14, 1961 w. s. BAKER ETAL 2,971,419

PERFORATING MACHINE WITH POSITIVE ACTING RETURN Original Filed Nov. 5, 1952 2 Sheets-Sheet 1 Fly? INVENTOR Walter Sco it Baker BYHowa-rd M- Dodge ATTORNEYS Feb. 14, 1961 w, s, BAKER r 2,971,419

PERFORATING MACHINE WITH POSITIVE ACTING RETURN Original Filed Nov. 5, 1952 2 Sheets-Sheet .2

Walter Scott Baker BYIiowar-d M Do g ATTORNEYS United States PERFORATING MACHENE WKTH POSITIVE ACTING RETURN Walter Scott Baker, Clearwater, Fla, and Howard Dodge, Marion, IntL, assiguors to The General Tire and Rubber Company, Akron, Ohio, a corporation of Ohio Original application Nov. 5, 1952, Ser. No. 318,908, new

Patent No. 2,809,959, dated July 30, 1957. Divided and this application May 1, 1957, Ser. No. 656,457

1 Claim. ((31. 83--588) This new invention relates to a machine for perforating or otherwise deforming strips and bands of resilient material and more particularly to a perforating machine having a positive-acting punch-return mechanism.

This application is a division of our copending application, Serial No. 318,908, filed November 5, 1952, now US. Patent No. 2,800,959.

An object of the invention is to provide a durable high speed perforating machine of simple inexpensive construction having positive-acting means for advancing and retracting the punch.

Other objects of the invention are to provide a punching machine which is not subject to excessive wear and break down and which is still relatively inexpensive to build and maintain.

Other objects and advantages become apparent from the following description of several embodiments of the invention made in connection with the accompanying drawing in which like numerals refer to like parts and in which:

Figure 1 showsa front elevation of a strip perforating machine embodying the subject invention;

Figure 2 is an end view of this machine taken along the line 2-2 of Fig. 1;

Figure 3 is an enlarged cross-section of the feed rolls taken along line 3-3 of Fig. 1;

Figure 4 is a plan view of the feed rolls, the punch impact lever, and the punch return crank;

Figure 5 is a side view with portions broken away of the feed rolls and the punch and die mechanism of the subject machine;

Figure 6 is an end view of the punch and die mechanism of the subject machine; and

and die mechanism. The flywheel and feed rolls are driven through a driving means comprising a motor 23, a gear reduction box 24 and a link belt and sprocket arrangement off the gear reduction box to the flywheel and top feed roll respectively. The flywheel itself is supported by brackets 28 and 31 mounted on upright posts 3, 1 and 16 which are in turn integral with the frame. The strip material 5 is supplied to the feed rolls from a reel 10 or other supply means located to the left of the motor. i

Fig. 3 shows the feed roll arrangement contemplated by the subject invention. In this arrangement, top feed roll 6 is driven by sprocket 34 keyed to its shaft or axle 9 titlQllghli flYfil. The shaft-in turn is supported by tion.

plates 42 and 43 located at either side thereof and rotates in roller bearings, needle bearings, bushings or the like. Top feed roll 6 comprises an outer cylinder or outer member 36 and an inner cylinder or inner member 38 with an annulus of rubber-like material 37 in substantial elongation and radial compression disposed or located between them. The top roll 6 is keyed to the shaft 39 through key 35. Obviously, other means can be employed to unite the sprocket and feed roll with the shaft such as press fittings or machine screws of various sorts. The outer contact face of outer roll 36 can be roughened as by a knurling or cross-hatching or other devices to increase its grip on the strip stock. Any such knurling, however, tends to mar the surface of the strip stock and as such is not particularly desirable except when necessary to provide friction and grip between the feed roll and strip stock.

The inner and outer cylinders of the top roll can be substantially parallel or can diverge at the center and converge near the edges as shown in Fig. 3. In any case, the inner member should be in a radially spaced relation to the outer member and substantially concentric with it to provide for the intermediate rubber annulus. Any of the resilient mountings in which the rubber annulus is in substantial elongation and radial compression are suitable for this purpose. United States Patent No. 2,572,215 to Swart issued October 23, 1951, United States Patent No. 2,517,791 to Hutton issued August 8, 1950, and United States Patent No. 2,598,115 to Dodge issued May 27, 1952, disclose several species of such mountings and further describe their characteristics.

The bottom feed roll 7 of the subject apparatus is mounted on single ball bearings 46 which are in turn mounted on shaft 47. The shaft is supported by plates 48 and 49. The surface of the bottom. feed roll can likewise be knurled or otherwise roughened to provide a better grip between it and the feed roll. I have found, however, that it is preferable to knurl or roughen the sur-' face of one feed roll only, preferably the driving feed roll and not the idler feed roll, so that one face of the strip is clear and unmarred and always presentable. The bottom feed roll of Fig. 3 can be replaced by a resilient feed roll similar to top feed roll 6 as desired. In most applications, I have found that only one of the two feed rolls need be a resilient roll and provide the resilient, torsional, take-up means required by the subject inven- This, of course, depends upon the thickness and rigidity of the material being perforated or otherwise deformed and the amount of take-up or wind-up required of the feed rolls during the actual punching or stamping operation. Furthermore, we preferably use only one resilient feed roll and drive this resilient feed roll and allow the other roll to rotate as an idler. In some cases, however, both feed rolls may be driven and may be resilient rolls as already described. In accordance with this invention, we preferably drive the resilient roll and not the rigid roll.

The feed rolls should be set so that they are not as far apart as the thickness of material being fed through them or so that they are slightly closer together than the thickness of material being fed through them. Thus a grip or initial compression on the strip material is provided. The resilient mounting and particularly the rubber annulus of the mounting gives as necessary to accommodate the strip material. 'In this way the resilient feed roll performs a dual function by providing a torsional springtake-up when the strip material is momengrip on the strip material as it-passes through the rolls.

and returns the punch to its initial position.

Figs. 4 to 7 illustrate the punch and die arrangement of the subject invention. In this arrangement, a punch 8 is mounted in slot 69 in punch block 67 and the punch block is in turn screwed toor otherwise made integral with top body block 59 or to the frame itself (see Figs. 5 and 7). The die 64 is mounted in die block 66 which is screwed to or otherwise made integral with bottom body block 61 or with the machine frame. As shown in Fig. 6, machine screws 78 screw the punch block 67 to the top body block 59 and machine screws 79 screw the die block 66 to bottom body block 61. Intermediate the punch and die and the body blocks is a slot or passage 65 for the strip 5. This passage is adapted to accommodate the various gauges of strip to be used and extends from the feed rolls to the punch and die and on through the apparatus. If desired, wear plates 62 and 63 may be provided on the body blocks to protect the body blocks against wear and to control the passage thicknesses. Pins 76 and 77 unite the body blocks with the frame and screw into the frame at the base thereof. The pins are removable to provide for adjustment of the body blocks such as by shimming or grinding. The plates 42 and 48 supporting the feed rolls are also screwed to the body blocks with machine screws 52 and 53 and are adjustable therewith.

The punch 8 is engaged by a hammer or punch lever 9 intermediate the punch and flywheel that is pivoted on pin 54 mounted on cars '73 on the top body block. Cams 13 on the flywheel strike hammer 9 as the wheel rotates and force and advance the punch 8 through the strip material. Punch 8 can also be provided with a knob or head of other conventional design integral with or resting upon it so as to absorb the blow from cam 13. Generally, however, it is preferable to provide a hammer or punch lever resting on the head of the punch and separate from the punch so as to minimize lateral forces against the punch and minimize punch breakage.

Bell crank 12 pivoted on pin 51 provides a positive punch return means to withdraw the punch from the strip material and complete the punching cycle. Bell crank 12 has two arms including an arm 71 which is approximately or roughly perpendicular to the punch and an arm 72 which is roughly parallel to the punch. The end 33 of the arm 71 fits in central longitudinal slot or opening 80 formed in the punch. This slot extends along the line or axis of movement of the punch as shown. The other arm 72 extends out from the pivot pin to a point adjacent the circumference of the flywheel and coextensive with the head of the punch. Cams 14 on the flywheel are set so as to strike the end 82 of arm 72 when it is in the raised position and the punch is in the down position (Fig. 7 Thus as the flywheel rotates, one of the cams 13 strikes hammer 9 or the head of the punch and forces the punch through the strip material and immediately thereafter one of the cams 14 strikes arm 72 The flywheel shown rotatescounter-clockwise so that cams 13 firststrike the punch impact lever and then earns 14 strike the punch return arm 72. It should be noted that arm 72 extends to the side of the wheel so as not to interfere with the other cams 13. If desired, a spring or rubber band SS can be attached to the end of arm 71 from extension rod 50 on one of the machine screws 78 to minimize chatter and provide smoother operation.

Pairs of cams 13 and 14 should be spaced and adjusted about the circumference of the flywheel to coordinate with the radius of the flywheel, number of cams on the flywheel, speed of rotation of the flywheel and punching cycle. Under some circumstances, usually with slow speeds of rotation and large radius flywheels, a plurality of single cams or actuating means maybe employedon the flywheel so that each cam strikes both the punch impact lever and punch return bell crank .arm. When regular and evenly spacedperforations are desired, the cams i should be evenly spaced about the circumference of the flywheel. Otherwise, the cams should be spaced in accordance with the spacing of the perforations.

The flywheel should be relatively heavy to provide adequate momentum and to securely mount the cams. The came 13 are evenly spaced about the circumference of the wheel and bolted to it with bolts 56, as shown in 5. Cams comprising ball bearings are found to be quite satisfactory and to minimize wear on both the impact lever and cam. A recess 81 (Fig. 2) is provided in the wheel for the cam. Cam 14 is bolted to the wheel with bolts 57 and can be adjusted in holes 58 as necessary. Generally only one of the cams need be adjustable and this preferably should be the bell crank arm cam. The wheel itself is mounted on hub 33 on axle 27 which is in turn supported by bearings in brackets 28 and 31.

The driving means for the machine shown comprises an electric motor 23 and gear box or gear reduction unit 24 mounted on the frame. Sprocket 19 on the axle 22 of the gear reduction unit drives chain belt or link belt 17 which drives sprocket 26 keyed to shaft 27 of the flywheel. Likewise, sprocket 21 on axle 2 2 drives belt 18 which in turn drives top feed roll sprocket 34. Obviously other driving means such as a pulley and V belt arrangement are equally satisfactory provided that they do not slip. The rotation of the wheel and feed rolls is preferably synchronized or coordinated for best results.

It is understood that the feed roll of the subject invention can be adapted to any punching, stamping,'coining, drawing, or other machine into which a strip of ma terial is continuously fed and in which the movement of the material is momentarily halted or arrested while it is deformed. The above machines are further characterized by having relatively short and rapid punching or deforming cycles so that the strip material is fed to it in a substantially continuous fashion. In any such cases, feed rolls according to the subject invention can be utilized to takeup and automatically compensate for the stoppage and then release the energy so stored and feed the material forward. It is also understood that the strip material can be bands or strips of ferrous metal, brass, copper and the like, or even plastics such as nylon and polyvinyl chloride.

it is apparent that in accordance with the provisions of the patent statutes various modifications of the invention may be made without changing the spirit thereof.

What we claim is:

A high speed perforating machine comprising a frame, a punch with a slot formed therein along the line of movement of said punch, a die mounted on said frame for receiving the lower end of said punch, means including a pair of feed rollers for feeding continuously a strip between said punch and said die, means on said frame siideably guiding and mounting said punch for vertical reciprocation, means for actuating said punch to cause high speed reciprocation thereof including a rigid swingable punch lever pivotally mounted on said frame and resting on the top of said punch and a flywheel mounted on said frame for rotation about a horizontal axis and having a series of regularly circumferentially spaced impact rollers mounted thereon for striking said lever at intervals to actuate said punch, motor means for rotating said flywheel and said feed rolls continuously in synchronism, and means for yieldably resisting move ment of the punch and for retracting the punch including a bell crank, an endless band ofelastic rubber, and a series of regularly circumferentially spaced rigid impact cams mounted on said flywheel, means mounting said bell crank on said frame to swing about a horizontal axis,

which is below the flywheel and said lever and parallel to said first-named axis, said bell crank having a first arm with one end portion fitting into said slot andhaving a second upwardly extending arm with an upper end portion movable into and out of the path of movement of said impact cams, the impact of each cam with-"said upper end portion causing the bell crank to move in a direction to lower said second arm and to elevate said first arm, whereby said first arm engages the punch at the top of said slot to raise said punch and said lever to a position wherein the lever is in the path of movement of said impact rollers, said bell crank having a projecting band-receiving portion at the other end of said first arm connected to the upper end of said band, and means connecting the lower end of said band to the frame and locating the band to resist downward movement of the first arm and to bias the punch upwardly to a position wherein the lever is in the path of movement of said impact rollers.

References Cited in the file of this patent UNITED STATES PATENTS Cook June 3, Schulz Mar. 6, Calaway Jan. 12, Nuss Mar. 7, Schroeder Jan. 23, Loeven June 16, Beaulieu Nov. 11,

FOREIGN PATENTS Great Britain Oct. 27, 

